First off, let me extend an advanced thank you to all of you on the HD
list. I think more than any other one, this forum has sometimes been a
bit of a one way street for film oriented DP's like myself seeking information
about this "newfangled" medium of HD. I'm now about to jump
into the HD world, so I hope to be able to share some future insights
down the road, but for the time being I remain in the dark ages.
Generally, my questions pertain to the Varicam and its value as a tool
for gathering images for compositing.
Let me give you the specifics :
I'm shooting a single-camera half-hour presentation pilot.
The directors/producers need to shoot this on HD with the new P+S Technik
(for 2/3" chip cameras) on the front of the Panasonic Varicam. The
Varicam (as well as the P+S Technik) is coming to us free, so we're pretty
much locked into that camera (as opposed to the Cine Alta, thought I don't
think that's an issue here since my concerns would be the same for either
Those concerns are primarily related to the five or six special effects
shots that we need to shoot. As it stands now they will be composited
on a "Combustion" system, and they range from green screen compositing
to a morphing shot. And here's the kicker...there's no money to record
to D5 for those shots as most other productions have done when needing
to composite. This is a very low budget production, shot over four days,
with the SFX work being spread out all over those days, almost all of
it on location in New York City.
So here are my questions :
Do you think we're going to be royally screwed if we try to do this post
work from the DVCPROHD compressed images?! Are we never going to be able
to pull clean mattes without recording to D5? Or will it just be a matter
of making it a nightmare for the post folks, yet they will still be able
to successfully create the effects? Also, what frame rate would you recommend
shooting for these effects (knowing that we will probably shoot the rest
of the show at 24P)?
Thanks VERY much in advance.
DP - NYC
We are able to pull acceptable keys from the DVCPro HD tapes for television;
we usually do this in Smoke, but the tool set in Combustion is virtually
the same. We also use Combustion, but our Compositor is more practiced
Please bear in mind that we do not finish in HD; currently all our post
is SD mastered to Digital Betacam. Also, I would hasten to add that we
do not attempt really tough keys with this format; no smoke, glass, etc.
Of course, "acceptable," is the real joker in the deck; what's
ok for a corporate video or short shots in a local commercial may not
be ok for your use. I strongly urge you to consider getting a D5 for the
I'm quite sure everyone on the list will urge you to shoot some test shots
first. I'm frankly quite concerned about what will happen to green screen
scenes shot with the P+S Technik.
As for frame rates, we always shoot our green screen FG material at 30
fps; you could always shoot at 24 fps, remove the pull-down with Cinema
Tools, and then composite, but if there is a lot of movement, the added
blur of longer shutter could also cause problems. Blurs are hard to key.
One more thing, we add green in the camera's color corrector menu when
shooting the FG.
>"One more thing, we add green
in the camera's color corrector menu >when shooting the FG."
What exactly do you mean by this? Wouldn't the addition of green (in the
camera overall) tend to pollute the FG itself, making it "more"
difficult to key?
I'm curious about this because we usually do what would ostensibly seem
to be the opposite. We generally add plus green to the lights illuminating
the green screen only, or in the case of bluescreen work, we tend to add
half blue to the background. With bluescreen, we've had very good luck
further isolating the key by using 103 or some light warming gel on the
FG object's backlight. Unfortunately, the logical counterpart for greenscreen
would be some form of light magenta on the backlight, which isn't very
realistic, at least on planet Earth.
Finally, we've had good experience keying from HD DVCPro tapes with the
Ultimatte plug-in for HD, even at 24 frames, but frankly, most of our
HD compositing has been done with fairly sedentary FG's. I will give the
30 frame rate a test soon though. Thanks for the suggestion. Looking forward
to seeing you at NAB to compare notes.
South Coast Film and Video
I'm referring to boosting the green saturation in the color correction
This does not seem to cause a problem of increasing the green in flesh
tone because there is so little green there to begin with.
I do plan to do some more testing, and I'll let you know the results.
>Finally, we've had good experience
keying from HD DVCPro tapes with >the Ultimatte plug-in
for HD, even at 24 frames, but frankly, most of our >HD compositing
has been done with fairly sedentary FG's.
A minor correction: the Ultimatte AdvantEdge plugin is not SD or HD; it
is truly resolution agnostic on any platform.
If your capture hardware and underlying editing or compositing program
can support a given resolution, the AdvantEdge plugin will work with it.
>I'm referring to boosting the
green saturation in the color correction >menu. This does not
seem to cause a problem of increasing the green >in flesh tone
because there is so little green there to begin with.
Using masking on any camera when shooting color screens for compositing
is not, in general, a good idea.
It is remarkably easy to adjust the masking in such a way that it looks
pleasing to the eye but generates technically non-existent colors (colors
which fall outside the color triangle).
The upshot is that it will generate a lovely collared edge on your foreground
objects where they meet the screen which almost all compositing software
will leave unmolested, assuming it to be a part of the foreground image.
Bob Kertesz wrote :
>A minor correction : the Ultimatte
AdvantEdge plugin is not SD or HD; it >is truly resolution
agnostic on any platform. If your capture hardware and >underlying
editing or compositing program can support a given >resolution,
the AdvantEdge plugin will work with it."
Sorry for the confusion, but when we tried to purchase the Ultimatte AdvantEdge
plug-in for our Boxx HD edit system, it was not available for the system's
edit interface, SpeedRazor. In other words, even though our capture hardware
and underlying editing program did support HD resolution, there was no
Ultimatte AdvantEdge plugin being made for it. Since we needed an "Ultimatte
plug-in for HD", we had to get the AdvantEdge plug-in for AfterFX
instead, which WAS being supported.
So yes, the Ultimatte AdvantEdge plugin is not SD or HD and is truly resolution
agnostic on any platform, but this would not seem to be the case with
all Ultimatte plug-ins, at least to my knowledge. Or am I missing something?
South Coast Film and Video
>Sorry for the confusion, but
when we tried to purchase the Ultimatte >AdvantEdge plug-in
for our Boxx HD edit system, it was not available for >the
system's edit interface, SpeedRazor.
That's correct. There are a number of underlying editing or compositing
applications the AdvantEdge plugin supports, but Speed Razor is not on
that list. The full list of supported programs can be found on my web
The older Ultimatte plugin did have Speed Razor support, but it was decided
to drop it for the current release.
I've done quite a bit of compositing with Varicam footage, and here a
couple of notes for you :
1) Your post people will not have problems with mattes.
Sure, it won't be as clean as 2K files scanned off a Spirit from 35mm,
but post artists have been pulling reasonable keys with NTSC for years.
So, DVCPRO HD won't be that big a problem.
2) If you're using AdvantEdge and Combustion, do NOT
use the OS-X version. It's insanely buggy, or at least it was as of January,
which is the last time we tried to use it. We had to composite about 100
VFX shots for an upcoming HD-originated miniseries. The main keying tools
we used were AdvantEdge on Combustion/WinXP, and The Foundry's Keylight
2.0 on Avid DS|HD.
To be honest, I really don't know if the bugs were because of Ultimatte
or Combustion, but either way, it was buggy enough as to be unusable on
OS-X in a tight deadline environment.
3) Do not overly backlight your shots. If the foreground
edges are blown out to white, there is a magenta ringing introduced at
the very edges of the foreground that is really hard to deal with, especially
on hair and other thin-edge images. It was the 80/20 rule for us. Most
of the keys pulled wonderfully, and we spent 80% of our time dealing with
that damned magenta ringing.